server-code.md

Server code

The server code consists of two file:

1. The server endpoint
2. The server session

Server Endpoint

The server endpoint must include the following elements:

1. It must extend the reactor class. This class takes the name of the interface appended with "Reactor". The reactor is a Java generic which takes as its argument the server session.
2. It must implement the createAgent method. This method is responsible for creating the server session.
3. It must implement the valiateJWTToken method. This method is responsible for authenticating the JWT authentication token.

An example of the server endpoint is shown below:

@ServerEndpoint(value = "/VideoCommand")
public class VideoCommandService extends VideoCommandReactor<VideoCommandSession> {

	private VideoCommandSession recorderSession;

	/**
	 * Constructor
	 */
	public VideoCommandService() {
	}

	@Override
	public VideoCommandSession createAgent(Session wsSession) {
		recorderSession = new VideoCommandSession(wsSession);
		return recorderSession;
	}

	@Override
	public JWT valiateJWTToken(String jwtToken) throws JWTVerificationException {
		try {
			JWTVerifier verifier = JWT.require(Algorithm.HMAC256("MySecret")).withIssuer("MyIssuer").build();
			JWT jwtAuthentication = (JWT) verifier.verify(jwtToken);
			if (jwtAuthentication.getExpiresAt() == null) throw new JWTVerificationException("Must include expiry date");
			return jwtAuthentication;
		} catch (Exception e) {
			throw new JWTVerificationException("Could not verify JWT token: " + e.getMessage());
		}
	}
}

Server Session

The server session must include the following elements:

1. It must extend the agent class. This class takes the name of the interface appended with "Agent". The reactor is a Java generic which takes as its argument the server session.
2. It must implement the onAgentAdded and onAgentRemoved methods. These methods are called when a server session is created and terminated.
3. It must override all the abstract RPC calls generated from the interface.

An example of the server session is shown below:

public class VideoCommandSession extends VideoCommandAgent {

	/**
	 * Constructor.
	 * @param wsSession the WebSocket session
	 */
	public VideoCommandSession(Session wsSession) {
		this.wsSession = wsSession;
	}

	@Override
	public void onAgentAdded(VideoCommandAgent managedAgent) {
	}

	@Override
	public void onAgentRemoved(VideoCommandAgent managedAgent) {
	}

	@Override
	public void continuousPanTilt(long videoId, int streamId, int panSpeed, int tiltSpeed) throws WsRpcException {
		try {
			sendVideoCommand();
		} catch (Exception e) {
			throw new WsRpcInternalErrorException("continuousPanTilt Error: " + e.getMessage());
		}
	}
}